Numéro
J. Phys. Colloques
Volume 49, Numéro C8, Décembre 1988
Proceedings of the International Conference on Magnetism
Page(s) C8-2145 - C8-2146
DOI https://doi.org/10.1051/jphyscol:19888960
Proceedings of the International Conference on Magnetism

J. Phys. Colloques 49 (1988) C8-2145-C8-2146

DOI: 10.1051/jphyscol:19888960

EFFECTS OF OXYGEN AND MAGNETIC IMPURITIES ON NUCLEAR RELAXATION ANOMALIES IN La-M-Cu-O (M = Ba, Sr) SYSTEMS

K. Kumagai, I. Watanabe, Y. Nakamura et H. Nakajima

Department of Physics, Faculty of Science, Hokkaido University, Sapporo, 060 Japan


Abstract
Nuclear quadrupole resonance (NQR) of 139La in La2-xMxCuO4 (M = Ba, Sr) have revealed unexpected enhancement of nuclear relaxation rate, 1 / T1 at T*c 10 K, suggesting the occurrence of magnetic instability in the low temperature region. In the undoped La2CuO4, oxygen deficiencies affect strongly the nuclear relaxation rate. Magnetic impurities (Fe etc.) suppress the enhancement of 1 / T1, but non-magnetic Zn does not. In the superconducting region, fluctuations of Cu moments at low temperatures seem to remain extremely fast as same as that at high temperatures.